Add some debug output utility functions.

 - Legacy-Id: 3262

Author: levkowetz

ietf/utils/debug.py

@@ -0,0 +1,74 @@
+
+import sys
+import inspect
+from pprint import pformat
+from django.conf import settings
+
+# A debug decorator, written by Paul Butler, taken from
+# http://paulbutler.org/archives/python-debugging-with-decorators/
+
+# Number of times to indent output
+# A list is used to force access by reference
+__report_indent = [4]
+increment = 2
+
+def set_indent(i):
+    __report_indent[0] = i
+
+def trace(fn):                 # renamed from 'report' by henrik 16 Jun 2011
+    """Decorator to print information about a function
+    call for use while debugging.
+    Prints function name, arguments, and call number
+    when the function is called. Prints this information
+    again along with the return value when the function
+    returns.
+    """
+    def fix(s,n=32):    
+        if len(s) > n+3:
+            s = s[:n]+"..."
+        s = s.replace('\n',' ')
+        return s
+    def wrap(*params,**kwargs):
+        call = wrap.callcount = wrap.callcount + 1
+
+        indent = ' ' * __report_indent[0]
+        fc = "%s(%s)" % (fn.__name__, ', '.join(
+            [fix(repr(a)) for a in params] +
+            ["%s = %s" % (a, fix(repr(b))) for a,b in kwargs.items()]
+        ))
+
+        print "%s* %s [#%s]" % (indent, fc, call)
+        __report_indent[0] += increment
+        ret = fn(*params,**kwargs)
+        __report_indent[0] -= increment
+        print "%s  %s [#%s] ==> %s" % (indent, fc, call, repr(ret))
+
+        return ret
+    wrap.callcount = 0
+    if settings.DEBUG:
+        return wrap
+    else:
+        return fn
+
+def show(name):
+    if settings.DEBUG:
+        frame = inspect.stack()[1][0]
+        value = eval(name, frame.f_globals, frame.f_locals)
+        indent = ' ' * (__report_indent[0])
+        print "%s%s: %s" % (indent, name, value)
+
+def pprint(name):
+    if settings.DEBUG:
+        frame = inspect.stack()[1][0]
+        value = eval(name, frame.f_globals, frame.f_locals)
+        indent = ' ' * (__report_indent[0])
+        sys.stdout.write("%s%s:\n" % (indent, name))
+        lines = pformat(value).split('\n')
+        for line in lines:
+            sys.stdout.write("%s %s\n"%(indent, line))
+
+def say(s):
+    if settings.DEBUG:
+        indent = ' ' * (__report_indent[0])
+        print "%s%s" % (indent, s)
+